1. Field of the Invention
The present invention relates to a temperature control system for controlling a temperature of an object to be processed (for example, a semiconductor wafer).
2. Description of the Related Art
It is important to manage a temperature of a semiconductor wafer during processing in order to perform high precision processing on a fine pattern of a surface of the semiconductor wafer in a semiconductor wafer processing apparatus. If the temperature of the surface of the semiconductor wafer can be optimally controlled as a process is performed, not only processing precision but also a selectivity or throughput can be improved. Currently, as the area of a semiconductor wafer has increased, radio frequency (RF) power applied to the semiconductor wafer has increased. In particular, when an insulating film is etched, high power in kilowatts is applied in order to increase an etch rate. Since impact energy of ions imparted to a semiconductor wafer is increased due to the application of the high power, a temperature of the semiconductor wafer is disadvantageously increased.
Accordingly, in a conventional temperature control system, a temperature of a susceptor is controlled by forming a flow path for a coolant in the susceptor on which a semiconductor wafer that is an object to be processed is held and flowing the coolant into the flow path. A temperature of the coolant is adjusted by a cooling apparatus or a heating apparatus in a coolant supply apparatus (for example, a chiller) to a target temperature, and then the coolant is supplied into the flow path (for example, refer to Patent Document 1).
In the conventional temperature control system, the semiconductor wafer processing apparatus and the coolant supply apparatus which is sub-equipment are generally installed away from each other (for example, the semiconductor wafer processing apparatus is installed on a second floor and the coolant supply apparatus is installed on a first floor), and a distance between the semiconductor wafer processing apparatus and the coolant supply apparatus is equal to or greater than about 10 m in many cases. As such, once the semiconductor wafer processing apparatus and the coolant supply apparatus are installed away from each other, since a time taken for the coolant whose temperature is adjusted by the coolant supply apparatus to be supplied to the susceptor in the semiconductor wafer processing apparatus is long, it is difficult to control a temperature of the semiconductor wafer in real time. Also, since the coolant is increased by an amount of the coolant circulating in pipes, overall thermal capacity is increased, and thus it is difficult to control a temperature.    [Patent Document 1] Japanese Laid-Open Patent Publication No. 2008-294146